Molecular Formula for Common Chemicals

Scientist holding a molecular model of a chemical formula
Rafe Swan / Getty Images
By
Anne Marie Helmenstine, Ph.D.
Anne Marie Helmenstine, Ph.D.
Chemistry Expert
  • Ph.D., Biomedical Sciences, University of Tennessee at Knoxville
  • B.A., Physics and Mathematics, Hastings College
Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels.
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Updated on January 03, 2020

A molecular formula is an expression of the number and type of atoms that are present in a single molecule of a substance. It represents the actual formula of a molecule. Subscripts after element symbols represent the number of atoms. If there is no subscript, it means one atom is present in the compound. Read on to find out the molecular formula of common chemicals, such as salt, sugar, vinegar, and water, as well as representational diagrams and explanations for each.

Water

Three-dimensional molecular structure of water, H2O.
Ben Mills

Water is the most abundant molecule on the Earth's surface and one of the most important molecules to study in chemistry. Water is a chemical compound. Each molecule of water, H2O or HOH, consists of two atoms of hydrogen-bonded to one atom of oxygen. The name water typically refers to the liquid state of the compound, while the solid phase is known as ice and the gas phase is called steam.

Salt

This is the three-dimensional ionic structure of sodium chloride, NaCl.
Ben Mills

The term "salt" can refer to any of a number of ionic compounds, but it is most commonly used in reference to table salt, which is sodium chloride. The chemical or molecular formula for sodium chloride is NaCl. The individual units of the compound stack to form a cubic crystal structure.

Sugar

This is a three-dimensional representation of table sugar, which is sucrose or saccharose, C12H22O11.

There are several different types of sugar, but, generally, when you ask for the molecular formula of sugar, you are referring to table sugar or sucrose. The molecular formula for sucrose is C12H22O11. Each sugar molecule contains 12 carbon atoms, 22 hydrogen atoms, and 11 oxygen atoms. 

H20
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By Anne Marie Helmenstine, Ph.D.

Alcohol

This is the chemical structure of ethanol.
Benjah-bmm27/PD

There are several different types of alcohol, but the one that you can drink is ethanol or ethyl alcohol. The molecular formula for ethanol is CH3CH2OH or C2H5OH. The molecular formula describes the type and number of atoms of elements present in an ethanol molecule. Ethanol is the type of alcohol found in alcoholic beverages and is commonly used for lab work and chemical manufacture. It is also known as EtOH, ethyl alcohol, grain alcohol, and pure alcohol.

Vinegar

This is the chemical structure of acetic acid.
Todd Helmenstine

Vinegar primarily consists of 5 percent acetic acid and 95 percent water. So, there are actually two main chemical formulas involved. The molecular formula for water is H​​2O. The chemical formula for acetic acid is CH3COOH. Vinegar is considered a type of weak acid. Although it has an extremely low pH value, the acetic acid doesn't completely dissociate in water.

Baking Soda

Sodium Bicarbonate or Baking Soda
Martin Walker

Baking soda is pure sodium bicarbonate. The molecular formula for sodium bicarbonate is NaHCO3. An interesting reaction is created, by the way, when you mix baking soda and vinegar. The two chemicals combine to generate carbon dioxide gas, which you can use for experiments such as chemical volcanoes and other chemistry projects. 

Carbon Dioxide

Carbon Dioxide
Ben Mills

Carbon dioxide is a gas that is found in the atmosphere. In solid form, it is called dry ice. The chemical formula for carbon dioxide is CO2. carbon dioxide is present in the air you breathe. Plants "breathe" it in order to make glucose during photosynthesis. You exhale carbon dioxide gas as a by-product of respiration. Carbon dioxide in the atmosphere is one of the greenhouse gases. You find it added to soda, naturally occurring in beer, and in its solid form as dry ice. 

Ammonia

This is the space-filling model of ammonia, NH3.
Ben Mills

Ammonia is a gas at ordinary temperatures and pressure. The molecular formula for ammonia is NH3. An interesting fact that you can tell your students is to never mix ammonia and bleach because toxic vapors will be produced. The main toxic chemical formed by the reaction is chloramine vapor, which has the potential to form hydrazine. Chloramine is a group of related compounds that are all respiratory irritants. Hydrazine is also an irritant, plus it can cause edema, headaches, ​nausea, and seizures.

Glucose

This is the 3-D ball and stick structure for D-glucose, an important sugar.
Ben Mills

The molecular formula for glucose is C6H12O6 or H-(C=O)-(CHOH)5-H. Its empirical or simplest formula is CH2O, which indicates there are two hydrogen atoms for each carbon and oxygen atom in the molecule. Glucose is the sugar that is produced by plants during photosynthesis and that circulates in the blood of people and other animals as an energy source. ​

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Helmenstine, Anne Marie, Ph.D. "Molecular Formula for Common Chemicals." ThoughtCo, Sep. 7, 2021, thoughtco.com/molecular-formula-for-common-chemicals-608484. Helmenstine, Anne Marie, Ph.D. (2021, September 7). Molecular Formula for Common Chemicals. Retrieved from https://www.thoughtco.com/molecular-formula-for-common-chemicals-608484 Helmenstine, Anne Marie, Ph.D. "Molecular Formula for Common Chemicals." ThoughtCo. https://www.thoughtco.com/molecular-formula-for-common-chemicals-608484 (accessed April 19, 2024).